And so it may be useful, for the congressional community as well as the throngs of well-wishers in town just for the festivities, to be reminded of some of the curious ways in which the customs of the day are different from all the others.

Just as every kid has the potential to be an A student until classes are underway, and every team gets to harbor hopes of a championship season until the first game is played, each senator and representative has the same theoretical shot at legislative and political success at the start of January in every odd-numbered year.

The quantifiable sorting really doesn’t get started until the new Congress is at least a few hours old, once the formalities have locked in place the partisan balance of power — in this case, the continuation into a third year of Republican control over both halves of the Capitol.

Just as the rhythms for the first day of a new academic year are unique, the opening ceremonies, beginning at noon, will feature some people who are out of the congressional spotlight on almost every other occasion, and some procedures that probably won’t be used again until January 2019.

Getting started on Jan. 3, which the 20th Amendment fixed as the first day for each congressional session since 1934, also provides Congress a brief period of unmatched attention and nearly unfettered power in those rare years — like this one — when a lame-duck president is packing up at the White House while his successor has to wait another two weeks or so to deliver his inaugural.

Watching the congressional ceremonies this time may also be particularly enjoyable for those political junkies across the country with a need for an infusion of civic optimism — because they take place in environment of collegiality everyone knows will devolve into partisan posturing almost as soon as the swearing-in Bibles are shelved and the extended families of the lawmakers start for the airport.

In the Senate

The undisputed star of the show will be someone with essentially universal name recognition but a pretty low profile at the Capitol: Vice President Joseph R. Biden Jr., who will probably be making his final official visit to the Capitol after a 44-year run that began with his arrival to become a freshman senator from Delaware a few weeks after his 30th birthday.

Biden, whose farewell got feted with a round of speechmaking and receptions just a few weeks ago, will be back as master of ceremonies because the Constitution says he’s also the almost always powerless president of the Senate. (In fact, Biden is about to become the 12th vice president, but the first who held the office longer than one term, who never got to exercise the position’s only true senatorial power-breaking a tie vote.)

On Tuesday, he’ll be in the chair to recognize Kentucky’s Mitch McConnell for his second term as majority leader, the parliamentary moment that cements the GOP’s hold on the place, and also recognize New York Democrat Charles E. Schumer as the new minority leader. He’ll also conduct the swearing in of 27 re-elected senators and seven newcomers (the smallest freshman class in 26 years).

But only then will his potential to create another wave of You Tube sensations arrive. Biden will repair to the Old Senate Chamber and stage oath-taking ceremonies with the senators and their families in front of a clutch of TV and still cameras — a spotlight he’s sure to relish to great comedic effect, as he has three times before. The highlight reel is sure to include taking selfies with anyone who asks, making funny faces with the toddlers and flirting with the daughters, mothers and granddaughters. (Two years ago, he used Cory Gardner’s cellphone to phone the Colorado Republican’s grandmother — and she hung up on him so she could focus on watching the antics on C-Span.)

Because two-thirds of the senators are holdovers from one Congress to the next, the Senate views itself as a “continuing body,” meaning that unlike the House it does not formally reconstitute itself every two years. And since the floor leaders, whose jobs are 20th century inventions, have already been chosen by their caucuses, there is no formal leadership election on opening day.

Instead, the most unusual procedural ritual is how the senators starting new terms line up alphabetically and come down the center aisle in groups of four, each customarily escorted by their predecessor or their state’s other senator. (Five of the seven freshmen will be paired in their two-person delegation with someone from the same party.)

After taking the oath (identical to the one used for all senior federal officials except the president) they are directed to a registry that’s been used since the Civil War to log the signatures of each senator being sworn in. (They get to keep the pens.)

In the House

The House of Representatives, as a parliamentary matter, essentially ceases to exist at noon, when the terms of all 435 members of the 114th Congress expire. And so the responsibilities of calling the new House to order, establishing that a quorum of members-elect have shown up (a constitutional requirement before business may begin) and conducting the balloting for speaker all fall to the clerk of the House.

Since 2011, that person enjoying that fleeting few hours of cable TV fame has been Karen L. Haas, who has otherwise adhered to the staffer’s code of shunning publicity during nearly three decades as a fixture in the ranks of senior GOP leadership aides.

The vibe in the House is considerably less formal but none the less antiquated than in the Senate. Custom holds that members may bring their non-adult children onto the floor during the day, and the rules about quiet in the visitor galleries are relaxed so that friends from home can hoot their approval when sighting their favorite newly minted member.

The result is a room overstuffed with an increasingly loud and unwieldy collection of partying constituents, glad-handing politicians and their kids, whose wide-eyed excitement in their Sunday best inevitably gives way to a collective and fidgety boredom.

Essentially, they are stuck in the chamber until mid-afternoon in that none of the members want to miss either their own swearing-in — or their five seconds of participation in the laborious but enormously consequential procedure beforehand. The election of the speaker is the only time every two years when the House votes with a clerk calling the roll alphabetically, after instructing the members-elect to “indicate by surname the nominee of their choosing.”

This will very likely be the least dramatic such election in a long while. Only a handful of Republicans, if that, are expected to vote against the election of Wisconsin’s Paul D. Ryan to his first full term in the job, which places him second in the line of presidential succession.

An absolute majority is required of those in the room is required for victory, meaning 24 from the GOP would need to turn on Ryan in order to block his re-election. Only nine confrontational conservatives opposed his first election, 15 months ago, during the first midterm speaker’s election in a quarter century. In contrast, his predecessor John A. Boehner knew his days were likely numbered when 24 of his colleagues refused to support him when the previous Congress got started in January 2015.

By longstanding custom, the just-elected speaker is the first House member to take office, and the oath is administered by the returning member (from either party) with the most seniority – Democrat John Conyers Jr. of Detroit, who is beginning his 27th term at 87, making him also the oldest member of the 115th Congress.